Your gear is not crap, there is room for improvement, but definitely not bad.
I always, always have had problems with PUGs on my server, are you doing strictly guild runs?
It depends on how your playing, but you've the effective health and the avoidance to handle raids, maybe not heroic raids yet, but definitely heroic 5mans.
You can get an addon that checks your incoming heals, like recount or recap or damage meters. Then you can check combat logs and find out what went wrong when you died, and the group wiped. Check to see if DPS is standing behind mobs, monitor incoming heals.
I'm suprised to see that you don't have armsman or expertise enchant on your gloves. And you don't have 24 stamina on your other ring... That's all the nit picking about gear I will do.
I don't see anything terrible at all about your spec either. Just that you don't have last stand. I really like last stand, it is very useful for my playstyle.
So, if your group is wiping, adapt your playstyle?
Are you demo shouting, tclaping and using shield wall and shield block? Are you using frenzied regeneration,
What's your rotation of skills?